The four major objectives of this proposal are: 1) To examine the form (secreted and/or membrane bound) in which effector cells (corneal epithelium) present their cytokines to target (corneal stromal) cells; 2) To determine the presence of specific receptors on the target cells and the characteristics of cytokine binding; 3) To examine the way in which the target cells present collagenase to their adjacent substrate; 4) To quantitate and compare the levels and locations of effectors, receptors, and collagenases in corneal development, growth, repair and ulceration in vivo with the same parameters in effector-mediated collagenase induction and inhibition in vitro. Purification of cytokines will be accomplished by a variety of chromatographic and electrophoretic methods now in use and by affinity purification on columns of bound monoclonal antibodies. Tagged cytokines will be used to examine cellular location and binding to target cells and substrate. The Xenopus oocyte system will be used to determine the amount and cellular location of the cytokines by procedures already in the literature for other biologically active substances.